(1) Field of the Invention
This invention relates to a device for a friction clutch for use in automobiles or the like, of the type in which a release bearing for controlling engage/release operation of the clutch is hydraulically operated.
(2) Description of the Prior Art
Hitherto, as described in, for example, Japanese Patent Laid-Open Publication No. 59-1820 (corresponding U.S. patent application Ser. No. 370,710 filed on 4/22/1982, now U.S. Pat. No. 4,620,625 and, U.S. patent application Ser. No. 459,184, filed on 1/19/1983, now U.S. Pat. No. 4,601,374) some type of friction clutch incorporates such an arrangement that a cylinder device for driving a release bearing is disposed adjacent the release bearing in a clutch housing.
According to such arrangement, the cylinder is formed with a cylindrical operation chamber (a hollow) and a cylindrical piston fits in the operation chamber. The piston projects outwardly from one end of the operation chamber, the projecting end of the piston being connected to the release bearing.
According to the above arrangement, a seal is provided to seal off the operation chamber, but it is inevitable that operation fluid leaks outward, though in very small amount, from a circumferential surface of the seal. Such leak fluid is likely to scatter about within the clutch housing, so that it deposits on friction facing and other parts. As a result, undesirable slippage may be caused to the friction facing. Another trouble is that any fluid affected part is easily liable to corrosion.
The object of the invention is to provide a release device for a clutch which eliminates the foregoing problems.